The present invention relates to an arrangement for coupling and decoupling gripper rail parts in a transfer press with coupling means in the mutually coordinated end parts of the gripper rail parts to be coupled with one another and to be clamped together as well as to a method for coupling and decoupling such gripper rail parts with the use of such an arrangement.
In transfer presses, deformation presses or similar Presses, the workpieces are seized by gripping tools and are deformed in the working stations. The gripping tools are installed at gripper rails which may extend from the workpiece input station by way of the working stations up to the workpiece output station. Two gripper rails are present for a safe gripping and transporting of the workpieces, whereby the two gripper rails are movable spaced with respect to one another in the direction of the transfer movement of the workpieces, in the direction of a lifting and lowering in relation to the tool sets and in the direction toward and away from one another.
During the refitting of the press for a new workpiece, in addition to the exchange of the tool sets, also the gripping tools have to be replaced. The gripper rails are subdivided for that purpose into gripper rail parts remaining in the press and into interchangeable gripper rail parts. The exchange of tool sets and gripper rail parts takes place by way of sliding tables which are adapted to be movable out of the press and into the same.
The decoupling of the gripper rail parts from one another and the coupling of the same with one another is a partial operation of the exchange and is controlled in time by way of the central press control.
Memory programmable controls for the press automation in the manufacturing operation and for the installation operation are known, for example, from the publications DE-A1-26 24 733 and EP-B1 0 010 170 (U.S. Pat. No. 4,314,354 corresponding to the latter).
It is known from the DE-A1-33 23 840 to couple five gripper rail parts of the gripper rail with the assistance of couplings and to separate the same from one another. The gripper rail parts are thereby separated from one another in the longitudinal direction.
Furthermore, in a press with gripper rails for the transport of workpieces, the use of clamping elements in end parts of the gripper rail parts, with a respective clamping bolt movable in its axial direction and about the same, for clamping the gripper rail parts is also known (assignee's own construction). The clamping bolt is adapted to be extended out of a gripper rail part over the area of the separating place and is adapted to be fixed behind a clamping surface in the gripper rail part to be coupled. A shaped part is taken along together with the clamping bolt which is adapted to be inserted into an aperture in the gripper rail part to be coupled for centering the gripper rail parts with each other prior to the clamping. The supply of adjusting means and of inquiry units as well as of the control and shifting lines takes place by way of couplings connecting lines, on the one hand, between the press supports and the gripper rail parts remaining in the press and, on the other, between the mutually facing ends of the gripper rail parts. The couplings of the first-mentioned type must thereby be closed first in order to be able to close the couplings of the second-mentioned type. In the operating condition, the supply takes place by way of an energy feed by means of a drag cable between a respective press support and a respective gripper rail. The disengagement of the coupling takes place in reverse sequence also by corresponding signal transmission from the central press control The gripper rail parts are adapted to be restrained at the press supports, respectively, at the sliding tables by way of restraining means.
In contrast thereto, it is the task of the present invention to considerably reduce the periods of time for the decoupling and for the coupling of the gripper rail parts within the overall period of time for the exchange and to carry out simultaneously time-consuming operations.
The underlying problems are solved according to the present invention in that the movable parts of the centering means and one coupling half each for the lines are secured at a common bridge guided in an end part of a respective gripper rail part and in that the bridge is displaceably secured at the clamping bolt displaceable together with the same in and opposite the axial direction thereof. In the method according to the present invention, the underlying problems are solved by the following steps: coupling of the gripper rail parts by activating the first clamping means, as viewed from the energy supply for the gripper rails, for the advance of the clamping bolt up to the closing of the first coupling serving the energy supply of the second clamping means, activating the second clamping means for the advance of the clamping bolt up to the closing of the second coupling for the third clamping means, activating the third clamping means and possibly further clamping means up to the closing of the fourth and possibly further couplings in sequence, activating the clamping means for the further advance of the clamping bolts into a rotary position, activating the clamping means for the rotation of the clamping bolts through 90.degree. in the rotary position, activating the restraining means for the disengagement of the restraining action between the press supports and gripper rail parts and between the sliding tables and gripper rail parts, simultaneously activating all clamping means for the retraction of the clamping bolts under abutment of the clamping anchors at the clamping surfaces of the gripper rail parts to be coupled and for pressing the gripper rail parts one against the other, and decoupling of the gripper rail parts in reverse sequence.
It is of particular advantage according to other further features of the present invention that all gripper rail parts are drawn together simultaneously into a gripper rail, and the gripper rail parts are pressed together after the rotation of all clamping bolts into the clamping position, and in that the gripper rail parts are decoupled simultaneously in a movement opposite thereto and are brought into a position spaced with respect to one another. The arrangement of all coupling-essential components on a common bridge not only reduces the number of subparts; instead, a high accuracy in the Positioning of the structural components and groups serving the centering and coupling is achieved thereby which are to be moved sequentially into engagement with the corresponding counterpieces.
It is additionally of advantage that the gripper rail parts are separated from one another in the simultaneous movement of the clamping bolts out of their abutment at the clamping surfaces into their rotary position, whereby the rotation of the clamping bolts can also take place simultaneously during the abutment at the countersurfaces at the gripper rail parts to be decoupled. The displacement travel of the clamping bolts can also be reduced in that the displaceable bridges are connected within the gripper rail parts with the clamping bolts, in which the clamping element is arranged. The number of the coupling elements is also considerably reduced by the arrangement of the clamping elements in the end part of the gripper rail parts opposite the energy supply. The arrangement of centering means and coupling halves within the end parts of the gripper rail parts reduces, in addition to the structural dimensions, the danger of damage during the support of the gripper rail parts on the sliding tables.